Indications of Lamitrin 50 mg
Lamitrin 50 mg is indicated for:Epilepsy-combination therapy in patients aged 2 years and older:
partial-onset seizures
primary generalized tonic-clonic seizures
generalized seizures of Lennox-Gastaut syndrome
Epilepsy-monotherapy in patients aged 16 years and older.Adults with Bipolar Disorder.
Theropeutic Class
Primary anti-epileptic drugs
Pharmacology
Lamitrin 50 mg controls epileptic seizures by inhibiting voltage-sensitive sodium channels, thereby stabilizes neuronal membranes and consequently inhibits presynaptic excitatory neurotransmitter (e.g., glutamate and aspartate) release.
Dosage & Administration of Lamitrin 50 mg
Monotherapy of seizures (adult and child over 16 years): Initially 25 mg once daily for 14 days, then 50 mg once daily for further 14 days, then increased by maximum 50 mg/day every 7-14 days; usual maintenance dose 225-375 mg/day in 1-2 divided doses.Adjunctive therapy of seizures with Valproate:
Adult and child over 12 years: Initially 25 mg on alternate days for 14 days, then 25 mg once daily for further 14 days, thereafter increased by maximum 25-50 mg/day every 7-14 days; usual maintenance, 100-200 mg/day in 1-2 divided doses.
Child 2-12 years: Initially 150 mcg/kg/day in 1-2 divided doses for 14 days (those weighing under 13 kg may receive 2 mg on alternate days for first 14 days), then 300 mcg/kg/day in 1-2 divided doses for further 14 days, thereafter increased by maximum 300 mcg/kg/day every 7-14 days; usual maintenance 1-3 mg/kg/day in 1-2 divided doses.
Adjunctive therapy of seizures (with enzyme inducing drugs e.g., Carbamazepine, Phenytoin, Phenobarbital, or Primidone) without Valproate:
Adult and child over 12 years: Initially 50 mg once daily for 14 days, then 50 mg twice daily for further 14 days, thereafter increased by maximum 100 mg/day in every 7-14 days; usual maintenance 300-500 mg daily in 2 divided doses.
Child 2-12 years: Initially 600 mcg/kg/day in 2 divided doses for 14 days, then 1.2 mg/kg/day in 2 divided doses for further 14 days, thereafter increased by maximum 1.2 mg/kg/day in every 7-14 days; usual maintenance 5-15 mg/kg/day in 2 divided doses (maximum 400 mg/day in 2 divided doses).
Monotherapy therapy of bipolar disorder (without enzyme inducing Drugs) without Valproate:
Adult over 18 years: Initially 25 mg once daily for 14 days, then 50 mg once daily for further 14 days, then 100 mg once daily for further 7 days; usual maintenance dose 200 mg once daily; maximum 200 mg daily.
Adjunctive therapy of bipolar disorder with valproate:
Adult over 18 years: Initially 25 mg on alternate days for 14 days, then 25 mg once daily for further 14 days, then 50 mg once daily for further 7 days; usual maintenance dose 100 mg daily; maximum 100 mg daily.
Adjunctive therapy of bipolar disorder (with enzyme inducing drugs with enzyme inducing drugs e.g., Carbamazepine, Phenytoin, Phenobarbital, or Primidone) without Valproate:
Adult over 18 years: Initially 50 mg once daily for 14 days, then 50 mg twice daily for further 14 days, then 100 mg twice daily for further 7 days, then 150 mg twice daily for further 7 days; usual maintenance 200 mg twice daily
Dosage of Lamitrin 50 mg
Epilepsy-Table-1: Escalation Regimen for Lamitrin 50 mg in Patients Older than 12 Years with Epilepsy
Weeks 1 & 2:
In patients not taking Carbamazepine, Phenytoin, Phenobarbital, Primidone or Valproate: 25 mg every day
In patients taking Valproate: 25 mg every other day
In patients taking Carbamazepine, Phenytoin, Phenobarbital or Primidone and not taking Valproate: 50 mg/day
Weeks 3 & 4:
In patients not taking Carbamazepine, Phenytoin, Phenobarbital, Primidone or Valproate: 50 mg/day
In patients taking Valproate: 25 mg every day
In patients taking Carbamazepine, Phenytoin, Phenobarbital or Primidone and not taking Valproate: 100 mg/day (in 2 divided doses)
Week 5 onward to maintenance:
In patients not taking Carbamazepine, Phenytoin, Phenobarbital, Primidone or Valproate: Increase by 50 mg/day every 1 to 2 weeks
In patients taking Valproate: Increase by 25 to 50 mg/day every 1 to 2 weeks
In patients taking Carbamazepine, Phenytoin, Phenobarbital or Primidone and not taking Valproate: Increase by 100 mg/day every 1 to 2 weeks
Usual maintenance dose:
In patients not taking Carbamazepine, Phenytoin, Phenobarbital, Primidone or Valproate: 225 to 375 mg/day (in 2 divided doses)
In patients taking Valproate: 100 to 200 mg/day with Valproate alone 100 to 400 mg/day with Valproate and other drugs that induce glucuronidation (in 1 or 2 divided doses)
In patients taking Carbamazepine, Phenytoin, Phenobarbital or Primidone and not taking Valproate: 300 to 500 mg/day (in 2 divided doses)
Table-2: Escalation Regimen for Lamitrin 50 mg in Patients Aged 2 to 12 Years with EpilepsyWeeks 1 & 2:
In patients not taking Carbamazepine, Phenytoin, Phenobarbital, Primidone or Valproate: 0.3 mg/kg/day in 1 or 2 divided doses
In patients taking Valproate: 0.15 mg/kg/day in 1 or 2 divided doses
In patients taking Carbamazepine, Phenytoin, Phenobarbital or Primidone and not taking Valproate: 0.6 mg/kg/day (in 2 divided doses)
Weeks 3 & 4:In patients not taking Carbamazepine, Phenytoin, Phenobarbital, Primidone or Valproate: 0.6 mg/kg/day (in 2 divided doses)
In patients taking Valproate: 0.3 mg/kg/day in 1 or 2 divided doses
In patients taking Carbamazepine, Phenytoin, Phenobarbital or Primidone and not taking Valproate: 1.2 mg/kg/day (in 2 divided doses)
Week 5 onward to maintenance:
In patients not taking Carbamazepine, Phenytoin, Phenobarbital, Primidone or Valproate: The dose should be increased every 1 to 2 weeks as follows-calculate 0.6 mg/kg/day
In patients taking Valproate: The dose should be increased every 1 to 2 weeks as follows-calculate 0.3 mg/kg/day
In patients taking Carbamazepine, Phenytoin, Phenobarbital or Primidone and not taking Valproate: The dose should be increased every 1 to 2 weeks as follows-calculate 1.2 mg/kg/day
Usual maintenance dose:
In patients not taking Carbamazepine, Phenytoin, Phenobarbital, Primidone or Valproate: 4.5 to 7.5 mg/kg/day (maximum 300 mg/day in 2 divided doses)
In patients taking Valproate: 1 to 3 mg/kg/day with Valproate alone 1 to 5 mg/kg/day (maximum 200 mg/day in 1 or 2 divided doses)
In patients taking Carbamazepine, Phenytoin, Phenobarbital or Primidone and not taking Valproate: 5 to 15 mg/kg/day (maximum 400 mg/day in 2 divided doses)
Table-3: The Initial Weight-Based Dosing Guide for Patients Aged 2 to 12 Years Taking Valproate (Weeks 1 to 4) with EpilepsyWeeks 1 & 2:
If the patients weight is 6.7 kg to 14 kg: 2 mg every other day
If the patients weight is 14.1 kg to 27 kg: 2 mg every day
If the patients weight is 27.1 kg to 34 kg: 4 mg every day
If the patients weight is 34.1 kg to 40 kg: 5 mg every day
Weeks 3 & 4:
If the patients weight is 6.7 kg to 14 kg: 2 mg every day
If the patients weight is 14.1 kg to 27 kg: 4 mg every day
If the patients weight is 27.1 kg to 34 kg: 8 mg every day
If the patients weight is 34.1 kg to 40 kg: 10 mg every day
Bipolar disorder-Table-4: Escalation Regimen for Lamitrin 50 mg in Adults with Bipolar DisorderWeeks 1 & 2:
In patients not taking Carbamazepine, Phenytoin, Phenobarbital, Primidone or Valproate: 25 mg daily
In patients taking Valproate: 25 mg every other day
In patients taking Carbamazepine, Phenytoin, Phenobarbital or Primidone and not taking Valproate: 50 mg daily
Weeks 3 & 4:
In patients not taking Carbamazepine, Phenytoin, Phenobarbital, Primidone or Valproate: 50 mg daily
In patients taking Valproate: 25 mg daily
In patients taking Carbamazepine, Phenytoin, Phenobarbital or Primidone and not taking Valproate: 100 mg daily (in divided doses)
Week 5:
In patients not taking Carbamazepine, Phenytoin, Phenobarbital, Primidone or Valproate: 100 mg daily
In patients taking Valproate: 50 mg daily
In patients taking Carbamazepine, Phenytoin, Phenobarbital or Primidone and not taking Valproate: 200 mg daily (in divided doses)
Week 6:
In patients not taking Carbamazepine, Phenytoin, Phenobarbital, Primidone or Valproate: 200 mg daily
In patients taking Valproate: 100 mg daily
In patients taking Carbamazepine, Phenytoin, Phenobarbital or Primidone and not taking Valproate: 300 mg daily (in divided doses)
Week 7:
In patients not taking Carbamazepine, Phenytoin, Phenobarbital, Primidone or Valproate: 200 mg daily
In patients taking Valproate: 100 mg daily
In patients taking Carbamazepine, Phenytoin, Phenobarbital or Primidone and not taking Valproate: up to 400 mg daily (in divided doses)
Interaction of Lamitrin 50 mg
Lamitrin 50 mg interacts with Oral contraceptives, Atazanavir/ritonavir, Carbamazepine, Levetiracetam, Lithium, Lopinavir/ritonavir , Olanzapine, Phenobarbital/primidone , Phenytoin, Pregabalin etc.
Contraindications
Hypersensitivity (e.g., rash, angioedema, acute urticaria, extensive pruritus, mucosal ulceration) to the drug or its ingredients.
Side Effects of Lamitrin 50 mg
Common side effects of Lamitrin 50 mg include-dizziness, tremor, headache, rash, blurred vision, fever, lack of coordination, abdominal pain, infections, sleepiness, back pain, vomiting, diarrhea, tiredness, insomnia, dry mouth, stuffy nose, sore throat.
Pregnancy & Lactation
Pregnancy category C. Either studies in animals have revealed adverse effects on the fetus (teratogenic or embryocidal or other) and there are no controlled studies in women or studies in women and animals are not available. Drugs should be given only if the potential benefit justifies the potential risk to the fetus.Nursing Mothers: Lamitrin 50 mg is present in milk from lactating women taking Lamitrin 50 mg.
Precautions & Warnings
Serious skin rashes, Blood Dyscrasias, Suicidal Behavior, Aseptic Meningitis can occur in both adult and pediatric population.
Overdose Effects of Lamitrin 50 mg
Overdose has resulted in ataxia, nystagmus, seizures (including tonic-clonic seizures), decreased level of consciousness, coma, and intraventricular conduction delay.
Storage Conditions
Store below 30°C. Protect from light and moisture. Keep out of the reach of children.
Use In Special Populations
Hepatic impairment: Dosage adjustments required in patients with moderate and severe liver impairment.Renal impairment: Reduced maintenance doses may be effective for patients with significant renal impairment.
Drug Classes
Primary anti-epileptic drugs
Mode Of Action
The exact mechanism of action of Lamitrin 50 mg is not fully elucidated, as it may exert cellular activities that contribute to its efficacy in a range of conditions. Although chemically unrelated, Lamitrin 50 mg actions resemble those of phenytoin and carbamazepine, inhibiting voltage-sensitive sodium channels, stabilizing neuronal membranes, thereby modulating the release of presynaptic excitatory neurotransmitters.Lamitrin 50 mg likely acts by inhibiting sodium currents by selective binding to the inactive sodium channel, suppressing the release of the excitatory amino acid, glutamate. The mechanism of action of Lamitrin 50 mg in reducing anticonvulsant activity is likely the same in managing bipolar disorder. Studies on Lamitrin 50 mg have identified its binding to sodium channels in a fashion similar to local anesthetics, which could explain the demonstrated clinical benefit of Lamitrin 50 mg in some neuropathic pain states.Lamitrin 50 mg displays binding properties to several different receptors. In laboratory binding assays, it demonstrates weak inhibitory effect on the serotonin 5-HT3 receptor. Lamitrin 50 mg also weakly binds to Adenosine A1/A2 receptors, α1/α2/β adrenergic receptors, dopamine D1/D2 receptors, GABA A/B receptors, histamine H1 receptors, κ-opioid receptor (KOR), mACh receptors and serotonin 5-HT2 receptors with an IC50>100 µM. Weak inhibitory effects were observed at sigma opioid receptors. An in vivo study revealed evidence that Lamitrin 50 mg inhibits Cav2.3 (R-type) calcium currents, which may also contribute to its anticonvulsant effects.
Pregnancy
Pregnancy Category C. Lamitrin 50 mg is excreted in human milk. Because of the potential for serious adverse reactions in nursing infants from Lamitrin 50 mg, a decision should be made whether to discontinue nursing or discontinue the drug, taking into account the importance of the drug to the mother.
Pediatric Uses
Pediatric Use:
Epilepsy: Safety and effectiveness of Lamitrin 50 mg used as adjunctive treatment for partial onset seizures were not demonstrated in very young pediatric patient's aged 1 to 24 months.
Bipolar Disorder: Safety and effectiveness of Lamitrin 50 mg for the maintenance treatment of bipolar disorder were not established in pediatric patient's aged 10 to 17 years.